The FBI has dismantled a global phishing ring and recovered more than $16 million in a crackdown on fraudulent email schemes. A total of 74 people were arrested across a number of territories, including the U.S. and Nigeria, with most of those arrested accused of taking part in a “business email compromise” scam.

Email phishing is an old scam but an effective one. It’s one of the most enduring social engineering attacks in the digital world and is said by some authorities to have led to the loss of more than $3.7 billion since the Internet Crime Complaint Center began tracking it, as per Ars Technica. That said, the FBI and Department of Justice have struck a blow to its global reach with this latest string of arrests.

In the U.S. 42 people were arrested, with a further 29 detained in Nigeria. Arrests were also made in Canada, Mauritius, and Poland, with all of those arrested involved in the phishing scam in some capacity. Reportedly it would involve a malicious actor sending emails to company employees and tricking them into giving the fraudsters access to financial credentials to transfer money. The FBI said that it had seized $2.4 million as part of the raids, with a further $14 million in fraudulent wire transfers also recovered.

“Fraudsters can rob people of their life’s savings in a matter of minutes,” said Attorney General Jeff Sessions. “These are malicious and morally repugnant crimes. The Department of Justice has taken aggressive action against fraudsters in recent months, conducting the largest sweep of fraud against American seniors in history back in February.”

The arrests involved a number of agencies, including the FBI, double digits of U.S. Attorney offices, the Secret Service, Postal Inspection Services, Homeland Security Investigations, and the Treasury Department, not to mention their counterparts in the various involved countries. The Department of Justice said that this string of arrests was a “model for international cooperation against specific threats that endanger the financial well-being of each member country’s residents.”